Over 7 million trailers haul 94% of the nation's cargo transporting items as diverse as fresh fruit, computers, steel, flowers, cattle, plastic, oil, compressed gas, US Mail and more. Other trailer classifications are dry bulk, reefers (refrigerated) and tankers, dry and liquid. Many trailers are now used as warehouses on wheels, often waiting several days and tires can loose air pressure in any number of ways.
Tires in most trailers normally operate at approximately 100 psi. However, traveling through hot climates such as the Arizona desert can cause the pressure in the tires to increase to dangerous levels increasing likelihood of a blow-out or other catastrophic failure. Traveling through mountainous terrain increases tire wear dramatically. Oil tankers that require proportionately more turning also increases wear on the tires. Additionally, improper air pressure significantly reduces the life of tires, as much as 50% in many cases.
A typical long haul trailer will experience tire pressure loss of up to 10% psi per week causing accelerated tire wear of 20-30%. Additionally the under inflated tires cause up to a 5.8% increase in fuel consumption. It has been estimated that over 20 million tires are damaged annually due to road hazards such as fallen bolts from other units, large pot holes, washboard interstates and railway tracks. The rubber compound that makes up the tire will also leak air over time.
The three largest operating costs associated with transporting goods are fuel, salaries of drivers, and tires. It has been estimated that tire failures account for more than 50% of all road cost. Air injection directly into trailer tires while traveling at high speed has been available only via cumbersome and cost prohibitive measures such as using a separate air compressor or pressurizing axles, for example. Maintaining correct air pressure in trailer tires could significantly reduce costs associated with transporting goods, by extending tire life up to 80%. Consequently, systems and methods are needed for maintaining the correct air pressure in trailer tires.